Electric switch



Dec. 4, 1945. E H AYERS ETAL' 2,390,344

ELECTRIC SWITCH Filed March l, 1944 l? Y -slxl ll NM l Inventors:

7 Edgar H. Ayers,

Arldrew 6. Elmendorf,

Their Attorney.

'Pmredpea 4,' 1945 ELECTRIC SWITCH OFFICE Edgar n. Ayers ma. Andrew G. Elmenaorr, schenectady, N. Y., assignors to General Electric Company, a vcorporation o! New York vAppuataim March 1 1944, serial No. 524,596` s claims. (ol. zoo-16) Our invention relates to electric switches, more particularly to switchesl of the interlocktype which are adapted for operation by a moving member such as a moving element oi' a contacter,

and has tor its object a simple, reliable and inf' expensive electric switch of this type.A

VIn carrying out our invention in one form, we provide a supporting member provided with'a longitudinal groove having overhanging side walls and a switch operating member slidably movable in this groove and provided with projections cooperating with the overhanging side walls so that the operating member-is held in the groove, At one end the support is provided witha wall ciosing the groove on which is a removable stop in position to be engaged by the operating member and prevent movement of the operating member to a disengaged position with respect to the overhanging side walls. By removing this stop the operating member may be moved to a disengaged position and then removed from the supporting member. The operating member is provided with transverse apertures in which yare mounted bridging members which cooperate with contacts mounted on the support. y

Por a more complete understanding of our invention, reference should be had to .the vaccom-- panying drawing, Fig. 1 of which is an elevation view of a switch embodying our invention showing the switch in its closed circuit position; Fig.

2 is a view similar to Fig. l but showing the switch in its open circuit position; Fig. 3 is a section view along the line 3-3 oi' Fig. 1 looking in the direction of the arrows; Fig. 4 is a section along the line 4-4 of Fig. 2 looking in the direction of the arrows; wbileFig. 5 is a section along the line 5 5 of Fig. 2 looking in the direction of the arrows.

Referring tothe drawing, our invention in one lform comprises a bese or support I made of electrically insulating material, and preferably `molded from a suitable material such as a phenolic condensation product. The supporting .member Il is elongated and rectangular in shape and provided with a longitudinal central groove II in which is slidably mounted a switch operating member. I2, also made of an electricallyinsulating molded material. This operating member is provided with a plurality of laterally extending apertures I3 in each of which is mounted a bridging member I4 made oi' electrically conducting material and having a switch contact Ii at each end cooperating with stationary contacts mounted on the supporting member I4.

The operating member lI2 is secured normally in the slot I I by means o! overhanging side walls for the slot with which cooperate projections or extensions on the oper-ating member. As shown, overhanging walls I6 and II are provided for theupper end of the slot, and similar overhanging side walls I8 and I9 are provided for the lower en of the slot. At its upper end the operating member has two projections 20 and 2i on opposite sides which slide under the overhanging walls -I6 and I1 whereby this end is provided with projections 22 and 23 which normally extend under'the overhanging walls I8 and I9 thereby to secure the lower end of the operating member. As shown in Fig. 2, the projections 20 and 2| are of substantial length to give greater strength and wear resistance at this upper end of the operating member, which is-adapted to be engaged by a moving member for movement of the operating member, The projections 22 and 23, as shown in Fig. 2, are relatively short lengthwise of the operating member.

As shown, the operating member is biased to its uppermost position seen in Fig. 1 by a helical compression spring 24 engaging its lower end and positioned between'the lower end oi' the operating member and a cross wall 25 on the supporting member extending across the groove, On this cross wall is a short cylindrical stop member 26 in position to be engaged by the oper ating member when it is pushed downward toits lowermost position, as seen in Fig. 2. 'This stop 26 is preferably made of metal. It fits over a cylindrical projection 21 on the cross wall so as to be held by the projection against lateral movement, the stop being heid by the spring 24 against the cross wall. The operating member and the bridging contacts carried by it can be removed by moving the spring 24 and the stop 26 and then moving the operating member downward to its lowermost position in which the projections are disengaged from the overhanging walls to pro- Ivide for lateral movement of the operating member out of the slot. It will be noted that the lower end of the operating member is provided with a cylindrical projection 28 which fits inside the upper end of the spring 24 and holds it in place,

At{its upper end the operating member is provided with a cylindrical extension or rod 28 which projects upward beyond the upper.v end of the supporting member I. It .is contemplated that this rod will be engaged by the moving member ating member to its lowermost position, as sbown in Fig. 2. This rod lies loosely in a semi-cylindrical lgroove provided for it at the end of the supporting member.

It will further be noted that for the purpose of decreasing the contact area, and hence friction between the support and operating member, the operating Amember is of sucnwidth in a direction crosswise of its length as to t loosely between the two pairs of overhanging walls I6, I1 and I8, I9 whereby these overhanging walls guide tive operating member in the plane of the drawing, as well as guiding and securing it against movement outward from the plane of the drawing. The rearward side of the operating member engages the bottom of the groove As shown, the operating member has a rectangularv square cross section, while the bottom of the groove I| is flat.

`It will be understood that the operating member and support can be made from any suitable length for any desired number of bridging contacts. As shown, especially in Fig. 3, the operating member is provided with three transversely extending apertures having walls identical in size and construction and only one of which I3 will be described in detail. On the upper and lower walls of this aperture I3, which walls extend transversely with respect to the direction of movement of the operating member, arecylindrical projections 30 and 3| which form seats for one end of a spring 32 having its other end bearing against the bridging contact I4. As shown, the bridging contact |4 is mounted to form a normally closed switch, as seen in Fig. 1, and consequently the spring 32 is below the bridging contact and tends to force it upward against the upper stop 30. The spring 24, however, is much stronger than the spring 32 and, in fact, is mu/h stronger than the combined strengths of aliyof the springs 32 so that normally the spring 24 forces the operating member upward toits closed circuit position, as seen in Fig l. This compresses the spring 32 somewhat by reason of the engagement of the bridging member with the stationary contacts before the operating member reaches its uppermost position determined by engagement of a shoulder 33 (Fig. 3) on the upper end of the operating member at the point where the rod 29 begins with a cross Wall at the upper end of the slot.

It will be observed that anormally open switch can be obtained by reversing the bridging member I4, i. e., turning it in the plane of the drawing through an angle of 180 degrees so that its contacts I5 at each end are on its lower side. The spring 32 is then placed on the upper side ofthe bridging contact so as to apply a force tending to move the bridging member downward against the stop 3|.

As shown in Fig. 5, the bridging member I4,

and also any other bridging member, is provided with guide and stop'projections 31 and 38 on its inner side which embrace the inner wall of the operating member I2 thereby to hold the bridging member against movement of the aperture.

Also, each` bridging member is provided with a central edge portion 39 (Fig. l) on one side which, in the normally closed position shown, is

bent downward. This is on the front edge portion opposite the guide projections 31 and '38. This edge` flange 39 is wide'enough to lprevent turning of the bridging member counterclockwise, as seen in Fig. 3, Aabout an axis perpendicular to the drawing. of course can be `turned clockwise into substantial parallel relation with the longer dimension of'its aperture for removal from the operating member.

As shown, the stationary contacts are secured on the upper and lower sides of supports 4|) and 4| secured by screws along opposite edges of the supporting member. On one side these supporting members are provided with screws 42, by means of which suitable electric conductors may be connected thereto for connection of the switch in an electric circuit.

Suitable electric connecting means is provided on the back of the support, preferably mounted in grooves in the support. Thus an electric connection 43 extends between the connection or binding post 44 and the support'40 so that, by connection to the supports 4| and 44, the bridging member I5 is included in an electric circuit. Similarly, an electric connection extends between the support 46 and the support 41 so that electric connections made with the supports 41 and 48 include the bridge member 36 in an electric circuit.

The switch shown has two circuits opened and closed by the two bridging members, and the bridging members may be arranged to be either normally opened or normally closed. Thus to change the two bridging members to make normally open switches, the bridging members are moved up each one aperture in the operating member and reversed, as described above, so that the contacts face the bottom of the drawing and the springs push the bridging members downward. The bridging member I4 will be reversed and transferred to the lupper aperture and will then be in a normally open circuit relation with the uppermost contacts on the contact supports and 4|, while the bridging member 36 will be 40 reversed and transferred to the middle aperture in the operating member. The bridging member 36 will then be in normally open circuit position with respect to the upper contacts 34 and 35 on the electrically conducting contact supports 46 an'd 48. With the bridging members thus reversed when the operating member is pushed downward to the position of Fig. 2, the bridging members engage each its stationary contacts and is in its closed circuit position.

Another feature is the rolling of each bridging member in a clockwise direction, as seen in Fig. 3, about an axis perpendicular to the drawing on the stationary contacts after engagement to a final position. 'I'his rolling action is effected by` the positioning of the cylindrical projection 5|) on the bridging contact to one side out of alignment with the twov contacts on the bridging member whereby the force of the spring 32, one

end of which encircles the projection 5U, is applied at one side of the centers of the contacts on the bridging member.' Thus, as seen in Fig. 3,

' the guide member 50 is positioned somewhat to the left of the contacts Il carried by the bridging member, and consequently when the convex surfaces of the contacts engage, a, rolling action is eected in a clockwise direction, as seen in Fig. 3, so that the 'bridging members are tilted'at an angle with the operating member.

While we have shown a particular embodiment of our invention, it will be understood, of course, that we do not wish to be limited thereto since many modifications may be made, and we therefore contemplate by the appended claims to cover any such modifications as fall Within the true spirit and scope of vour invention.

The bridging member. however,

What we Vclaim as new and desire to secure by ing support, an operating member made of electrically insulating material slidably mounted on said support, an aperture in said operating member extending transversely o! its direction of movement, a projection on each of two opposite walls of `said aperture extending transversely with respect tothe direction of movement of said operating member, an electrically conducting bridging switch member extending through said aperture, a helical spring in said aperture having j one end encircling one oi.' said projections andl its other end bearing on said bridging member thereby to apply a force tending to hold said bridging member on said opposite projection, movable contacts on said bridging member, and stationary contacts on said support arranged to be engaged and disengaged by said contacts on said ibridging member upon movement of said operating member.

2 A switch comprising an electrically insulating support, an elongated operating member made of electrically insulating material slidably mounted on said support, a plurality of transversely extending apertures in said operating member, a projection on each of the two opposite walls of each of said apertures extending transversely with respect to the direction of movement of said operating member, said projections being each substantially central of its said wall and said projections being substantially opposite each other in each of said apertures, an electrically conducting bridging member extending through each of said apertures, a helical spring in each of said apertures having one end encircling one of said projections and its other end bearing on its said bridging member thereby to apply a force tending to bring said bridging member to rest on the opposite projection in said aperture, and stationary contacts on said support adjacent the ends f said bridging members arranged to be engaged and disengaged by said bridging members upon movement of said operating member.

3. A switch comprising an electrically insulating support, an operating member made of electrically insulating material slidably mounted on said support, an aperture in said operating member extending transversely of its direction of movement, a projection on each of two opposite walls of said aperture extending transversely with respect to the direction of movement of said operating member, an electrically conducting bridging switch member extending through said aperture, a helical spring in said aperture having one end encircling one of said projections and its other end bearing on said bridging member thereby to apply a force tending to hold said bridging member on said opposite projection, movable contacts on said bridging member, stationary contacts on said support arranged to be engaged and disengaged by said contacts on said bridging member upon movement of said operating member, and a projection on said bridging member encircled by said other end of said spring arranged at one side of a line joining said movable contacts thereby to cause said bridging member to roll on said stationary contacts.

.4. A switch comprising an elongated support made of electrically insulating material provided with a longitudinally extending groove having oppositely disposed overhanging side walls, an elongated contact operating member made of electrically insulating material slidably mounted in said groove, a pair of projections on said opery ating member `extending from opposite sides of said operating member and positioned between said overhanging side walls and the bottom of v said groove whereby said operating member is held slidably in -said groove, a cross member on said support closing one end ofmsaid groove, al stop member on said cross member for said operating member, said stopv member being removable to provide for slidable movement of said operating member toward said end to a disengaged position in which said pairs .of projections are in disengaged relation with said overhanging walls to provide for removal of said operating member from said groove, said stop member engaging the adjacent end of said operating member to prevent movement of said operating member to said disengaged position,

movable contact member on said operating mem-f said operatingmember extending from opposite sides o! said operating member and positioned between said overhanging side walls and the bot- 'tom of said groov whereby said operating member is -held slidably in said groove, an operating extension on one end of said operating member extending through said groove and projecting jfrom one`end of said support, fa cross member on said support closing the other end of said groove, a stop member on said cross member for said operating member, said stop member being removable to provide for slidable movement of said operating member toward said end to a disqv engaged position in which said pairs oi projections are in disengaged relation with Said overhanging walls to provide for removal of said operating member from said groove, said stop mem-v ber engaging the adjacent end of said operating member to prevent movement of said operating member to said disengaged position, transversely extending bridging contact member on said operating member, stationary switcln contacts mounted on said support adjacent the ends oi' said bridging members, and a spring positioned f between said cross member and the adjacent end of said operating member for biasing said operating member longitudinally to hold said bridging members in a predetermined relation with said stationary contacts.y

' and the bottom of said groove whereby said operating member is held slidably in said groove, an operating extension on one end of said operating member extending through said groove and projecting from one end of said support, a cross member on said support closing the other end of said groove, a stop member on said cross memy extending through said apertures, each ber for said operating member. said stop member being removable to provide for slidabie movementy oi said operatingmember toward saidV end to a position` in which said pairs of projections are in disengaged relation with said overhanging walls to provide for removal of said operating member from said groove, said stop member engaging the adjacent end of said operating member to prevent movement of said operating member to said disengaged position, said operating member being provided with transversely extending apertures, transversely extending bridging contact members of said bridging members being provided with projections embracing said operating member for holding i5 EDGAR H. 'AYERs ANDREW G. ELMENDORF. 

